This mega list of 100 app contain the most popular posts we have written since the start of Smart Apps for Kids back in 2011. I dug through thousands of posts and found the Top 100 Completely FREE Preschool Apps (no in-app purchases).

Though I am calling it a Top 100, that is the number of posts containing completely free apps. There are actually a total of 572 FREE apps! Yes, 572 apps that will cost you nothing and do not contain in-app purchases for anything. Enjoy and be sure to share with your friends!

21. Beginning Phonics

Touch, action and music engage children with beginning phonics. Based on the most current reading research, zippy tunes and hilarious animation reinforce each correct choice. Easy set up lets kids work on many letter sounds, or just a few.

22. Sesame Workshop (Twelve apps)

Big Bird, Ernie, Elmo and the gang have done well keeping up with the times and can now be found on your iDevice! Out of their heaps of apps and these are FREE! In true Sesame form these apps are not only entertaining but also have a great, quality educational value that shouldn't be passed up.

23. Chuggington - Be Safe

'Think Safe, Ride Safe, Be Safe!' is a new public service program that aims to provide child transportation safety guidance to families with young children. The program is brought to you by The National Highway Traffic Safety Administration (NHTSA), and Ludorum, the producers of the Chuggington™ television series.

24. 9 in 1 Children Games

This app includes 9 free educational games from the best children games development company. Only in HD quality. It is the perfect opportunity to try out 9 different amazing games for free.

25. Rosetta Stone® Kids Lingo Letter Sounds

Practice early reading skills and speak Spanish to control the action! Tons of toys are trapped in bubbles! Can you rescue them before they float away? Match the correct starting letter sound to release each toy and collect it. Speak Spanish words and phrases aloud to really get the party started! Use new Spanish vocabulary—including dance, throw, and jump—to amp up the fun!

26. Elephant's Bath

Elephant’s Bath is an interactive book for children aged 1-10. It is the story of a young girl, Zara and an Elephant. One day, Zara was at home when she heard a dripping sound. Where was it coming from? Is there an elephant in the bath?

27. Hideout: Early Reading

Hideout teaches kids how to read through a series of fun activities that emphasize letter-sound association and word repetition.

These activities make use of blending and reading short vowel words within meaningful contexts. Interactive activities highlight a core of words that share a phonic pattern. Engaging activities, set within relevant situations, provide meaning and purpose for reading and creating words.

28. NASA (Thirty-five apps)

There is nothing more fascinating, in my opinion, than aeronautics and space. So I have compiled a list of all NASA apps in order of popularity on iTunes for all our space buffs--young and old.The best thing about these apps? They are all completely FREE with no in-app purchases.

29. Geoboard

The Geoboard is a tool for exploring a variety of mathematical topics introduced in the elementary and middle grades. Learners stretch bands around pegs to form line segments and polygons and make discoveries about perimeter, area, angles, congruence, fractions, and more.

30. "I Like" book series (Twenty-four apps)

All "I Like" picture books contain engaging stories written by Miranda Paul and stunning crisp photographs. Words are highlighted as they are read to optimize the learning curve.

Literally everything in the "I Like" books is customizable; add your own voice, your own photos and even your own storyline!

Don't miss any of the Top 100 Completely FREE Apps for Preschoolers! No In-App Purchases! Here are links to all ten pages: